Is this a good real estate buy?

Having years of experience in the real estate as a realtor in Singapore, I've dealt with sales, rental and project development. I've dealt too with clients who made mistakes and are unable to backtrack from their deals. Although prices may vary internationally, the fundamentals of real estate deals are the same throughout.
I will share the following basics;
~ location, location, location! (And timing)
~ What is a good rental?
~ What is a good sale?
~ rental yield as compared to capital gain